dma-mapping: move dma_mark_clean to dma-direct.h

And unlike the other helpers we don't require a <asm/dma-direct.h> as
this helper is a special case for ia64 only, and this keeps it as
simple as possible.

Signed-off-by: Christoph Hellwig <hch@lst.de>

arch/arm/include/asm/dma-mapping.h

@@ -109,8 +109,6 @@ static inline bool is_device_dma_coherent(struct device *dev)
 	return dev->archdata.dma_coherent;
 }
 
-static inline void dma_mark_clean(void *addr, size_t size) { }
-
 /**
  * arm_dma_alloc - allocate consistent memory for DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices